The present invention relates to intravascular guide wires, and methods of manufacture thereof. In particular, the present invention relates to an intravascular guide wire, and methods for the manufacture thereof, with improved properties to enhance the use thereof.
Guide wires are used in various procedures in both the coronary regions and the peripheral regions of the body. Various sizes and lengths of guide wires are made to be suitable for various uses and locations in the body. For example, guide wires of a very small diameter, on the order of 0.010 to 0.018 inches may be suitable for use in narrow coronary vessels. Such guide wires may have an extremely floppy tip distal tip which may be bent or preformed by the physician to facilitate placement of the guide wire at the desired location. Other guide wires have larger diameter, for example 0.035 inches. These larger diameter guide wires may be especially useful in peripheral regions of the body. Larger diameter guide wires may be provided with very flexible tips or with relatively rigid tips depending upon the particular needs of the patient and the preferences of the physician. Guide wires come in a range of sizes in addition to those discussed above.
Some of the characteristics preferred in guide wires by some physicians include strength, the ability to provide a track for a balloon or other device to advance over, and good torsional transmittance. A discussion of these and other preferred characteristics of guide wires is in Endovascular Surgery, by Moore, W. S. and Ahn, S. S; p. 157, W. B. Saunders Co. (1989). One of the characteristics considered desirable by some physicians in a guide wire is that it should be easy to grip and use manually at the proximal portion.
Accordingly, it is an object of the present invention to provide a guide wire with favorable characteristics.
According to a first aspect of the invention, there is provided a guide wire, and a method for the manufacture thereof, having a core and a plastic jacket enclosing the core. The plastic jacket comprises a proximal portion formed of a first plastic material and a distal jacket portion formed of a second plastic material. The distal end of the proximal jacket portion and the proximal end of the distal jacket portion are of substantially equal outer diameters so as to form a smooth transition between the proximal and the distal jacket portions.
According to another aspect of the invention, there is provided a guide wire, and a method for the manufacture thereof, with a core that is selectively formable in at least a distal portion thereof, and a plastic jacket encasing the selectively formable core. The plastic jacket has a distal portion with a hydrophilic coating and a proximal portion without a hydrophilic coating.
According to another aspect of the invention, there is provided a guide wire, and a method for the manufacture thereof, having a core that is selectively formable, at least in a distal portion thereof, and a plastic jacket encasing the core. The plastic jacket has a distal portion that is more radiopaque than a proximal portion.